How to javascript function from dropdownlist?

I have javscript function which I want to call from dropdownlist.If I call javascript function from onchange event of dropdownlist from page_load,my dropdownlist's selectedIndexchanged event does not fire.How to handle it?.I want to call both javascript function and selectedindexchanged from dropdownlist.

}Suppose I have button control and want call javascript function from button.I will call javascript function from button's onclientclick event,after that my button's click event fire.I want like that in dropdownlist.

ScriptManager.RegisterStartupScript -- > which use to call the client side function in server side "text" is the name you can give any name for that script we mention CallSubject() : where we call our exact client side function

onchange event is from client side and on_selected index change is from server side, first onchange event gets triggered if it returns TRUE then it automatically call selectedIndexChanged otherwise it won't.basically you need to keep 'autopostback' property of dropdown list set to 'true'ThanksKoolprasd2003Editor, DotNetSpider MVMMicrosoft MVP 2014 [ASP.NET/IIS]